Thirty-day mortality rates after immunotherapy initiation.

Background: The aim of this study was to determine the cause of death in patients who died within 30 days after the first dose of immunotherapy. Methods: The data of 1432 patients treated with immunotherapy in six tertiary referral hospitals were retrospectively analyzed. Results: It was determined that 34 (2%) of the patients died within 30 days after the first dose of immunotherapy. Death occurred in all patients who received palliative therapy, and most patients (88%) received immunotherapy as second- or subsequent-line of therapy. The most common cause of death was disease progression and thromboembolic events. Conclusion: Preliminary results of the current study might give some clues to define the patient population in whom the fatal side effects of immunotherapy might be encountered.